Ozone has a very strong oxidising power. It is used in a number of fields including sterilisation, decolourisation and deodorisation. Electrolysis of water, preferably pure water, produces ozone through the following anode reaction:3H2O→O3+6H++6e−
The ozone produced may be dissolved in water, so called ozone-water. Ozone-water has been used in sterilisation in fields such as food processing, sanitary facilities and medical services. Ozone sterilises by oxidation, which inhibits both organic and inorganic matter.
The use of ozone-water as a sterilising agent has a number of benefits including the release of non-toxic by-products, oxygen and water. In contrast, ethylene oxide, a common sterilisation agent for medical device sterilisation, is very toxic. Consequently, sterilisation with ethylene oxide requires a long aeration time.
It is conventional to use a PbO2 anode for ozone generation. This anode material is subject to erosion under the application of very large current densities. In addition, it is undesirable to treat drinking and washing water with an electrode comprising lead. Diamond electrodes, in particular boron-doped diamond electrodes, are useful for electrochemical applications owing to a number of properties, which are significantly different to the properties of other electrode materials such as glassy carbon or platinum. These properties include the high hardness, high thermal conductivity and chemical inertness associated with diamond and the wide electrochemical potential window of conductive diamond.